Apparatus for continuous melting loose products

ABSTRACT

Apparatus for continuous melting of free-flowing solid products containing a reservoir inside of which is disposed a heating pipe with one end in communication with a connection for the charging of free-flowing solid product and the other end being open. In the pipe is inserted a worm. Openings are formed in the wall of said pipe for recirculation of a molten mass.

United States Patent 11 1 Sholk et a1. Nov. 20, 1973 APPARATUS FOR CONTINUOUS MELTING 1,560,826 II/l925 Kirschbraun 126/3435 A x LOOSE PRODUCTS 2,367,149 1 1945 [76] Inventors: Semen Fedorovich Sholk,

Zvenigorodskoe Shosse, 3a, kv. 223; Jury Ruvimovich Svidler, Znamenskaya ulitsa, 35, kv. 22; Viktor Petrovich Seleznev, Bolshaya Filevskaya ulitsa, 41, korpus 5, kv. 2; Zinaida Petrovna Komova, 1 Novo-Tatarskaya ulitsa, 3, kv. 4, all of Moscow, U.S.S.R.

[22] Filed: Aug. 2 5, 1971 [21] Appl. No.: 174,762

[52] US. Cl 126/3435 A, 23/280, 165/108, 165/109 [51] Int. Cl. F24h l/00 [58] Field of Search 165/108, 109, 87; 126/3435 A; 219/421; 23/280 [56] References Cited UNITED STATES PATENTS 285,736 9/1883 Dopp 165 108,

Smith 165/109 X FOREIGN PATENTS OR APPLICATIONS 532,832 11/1954 Belgium 165/109 1,068,222 1l/1959 Germany 165/87 666,981 1 [[1938 Germany 165/108 Primary Examiner-Albert W. Davis, Jr. Attorney-Holman & Stern 3 wall of said pipe for recirculation of a molten mass.

5 Claims, 1 Drawing Figure APPARATUS FOR CONTINUOUS MELTING LOOSE PRODUCTS This invention relates to equipment for carrying out processes of chemical technology and more particularly to apparatus suitable for continuous melting loose products.

Known in the prior'art is an apparatus for continuous melting loose products containing a heating reservoir,

provided with connections to charge the loose product and to draw-off the melt. A mixer is installed inside the reservoir. A g

This apparatus, however, has low productivity for lack of intensive heat and mass exchange, since heat necessary for carrying out the melting process is transmitted only through the walls of the reservoir, while the mixer isnot capable of providing sufficiently intensive inter-mixing. v

In addition, such apparatus is inconvenient for melting sublimable substances because of rapid deposit formation in connection with the charging of loose material in the upper part of the apparatus.

Also known in the prior art is apparatus for continuous melting of loose products containing a heating reservoir having a cover which is provided with a connection for the charging of the loose material. There is a connection in the wall of said reservoir forthe draw-off of melt in which the bottom part of the melting compartment communicates with the riser pipe arranged outside the reservoir. Pump and heat exchanger means are disposed in said riser pipe conduit.

A strainer insertion of complicated shape, preventing access of the hard loose material to the interior of the draw-off melt connection is arranged under 'theconnection for the charging of loose product.

Loose product charged through the connection in the top of the apparatus falls on the surface of a molten mass in the reservoir and melts.

A portion of themolten mass is drawn-off from the reservoir alonga recirculation pipe, being heated in a heat exchanger and the hot molten mass is returned into the reservoir.

This known apparatus has the disadvantage that the surface of contact between loose product and molten mass as well as immersion of particles of loose material into said mass are hampered by adsorbed air contained in the loose product, which reduces the productivity of the apparatus.

The known apparatus has a long starting up period caused by the impossibility of recirculatory system operation before the molten mass is formed in the reservoir.

In addition, the speed of molten mass movement in the reservoir, entering the reservoir from the recirculation pipe, drops as the molten mass flow approaches the draw-off connection, which causes a decrease in the massand heat exchange of the melt. Because of this disadvantage, since the geometric dimensions of the apparatus and reservoir cannot be increased, consequently productivity of the apparatus cannot reach sufficiently high values.

The known apparatus cannot be used for operation under conditions of an inert gas atmosphere and pressure because of the leakage of gas by pump into the heat exchanger, which makes more difficult both the heat exchange and melting process.

Operation of the known apparatus with sublimable products is hampered by the deposit formation in connection with the charging of loose product as well as because of space in the reservoir above the melt.

An object of this invention is to provide an apparatus for continuous melting loose materials in which together with simple construction it is possible to realize the following steps: forced immersion of loose material into the molten mass; an increase, as compared with conventional apparatus, of the surface of contact of loose material, with the molten mass; the improvement of heatand mass exchange; the elimination of the starting up period of the melting process; and operation under conditions of an inert gas atmosphere and pressure as well as operation with sublimable substances.

This is attained by apparatus for continuous melting of loose products containing a heating reservoir provided with connections for the charging of loose product and for the draw-off of melt and equipped with melt recirculation means wherein, according to this invention, said recirculation means comprises a heating pipe inserted in the reservoir, provided with openings formed in its wall, inside of which is located a worm, one end of said pipe communicating with the connection for the charging of loose product, while the other end is open.

The proposed apparatus for continuous melting of loose products provides for uninterrupted introduction of said products by means of the heating pipe. In the apparatus the loose products are melted in the process of being charged into the reservoir, which eliminates the starting up period of the apparatus operation.

In the process of operation, when the reservoir of the apparatus has already been filled with they molten mass, flood wetting of the charge by heating pipe loose product with the circulating molten mass, considerably increases productivity of the apparatus, as compared with conventional constructions.

Hermetic introduction of loose products into the apparatus reservoir and utilization of the'worm, which removes deposits from the wall of the pipe, facilitate conducting the process of melting of readily sublimable substances.

The proposed apparatus is compact construction.

Further the invention will be apparent from the description of an exemplary embodiment taken in conjunction with the accompanying drawing in which is schematically shown an elevation of the apparatus for continuous melting of loose products according tovthe present invention.

The apparatus includes a cylindrical heating reservoir 1 having conical bottom 2 and cover 3 on which drive4 is mounted. The drive 4 is connected to shaft 5 on which worm 6 and mixing means 7 are mounted. Worm 6 extends axially through pipe 8 which comprises a chamber for preliminary melting of loose product. The chamber formed by pipe 8 is provided with a heater means, for example, in the form of a heating jacket 9 having nozzles 10 and 11 for the inlet and outlet, respectively, for a suitable of the heating medium respectively. Openings 12 are formed in the wall of pipe 5 for recirculation of melt. One end of pipe 8 chamber communicates with an upper connection 13 to recieve a charge of the loose product being melted, while the other end of said pipe 8 is open, pipe 8 is provided with packing 14 for shaft 5.

Reservoir l is surrounded with a heating jacket 15 which is provided with nozzles 16 for inlet of heating and simple in medium and nozzles 17 for outlet of said medium. A draw-off connection 18, for melt, extends from the side wall of reservoir 1, complete discharge of the melt from reservoir 1 is provided by tapping connection 19.

The apparatus for continuous melting loose products operates as follows:

The loose product is charged into the reservoir 1 through connection 13 as heat supplied is given by the jacket 9 to pipe (chamber) 8 and mixing means 7 is operated. The charged product drops on the upper blade of worm 6 which conveys it to the conical bottom 2.

When loose product passes through heated pipe 8 it undergoes a preliminary melting due to the heat given out by the heating medium through heating jacket 9 via the nozzles 10, 11.

The molten product accumulates in the lower part of reservoir 1, and gradually fills it up to the level corresponding to connection 18 and draw-off is accomplished through said connection.

During further operation of the apparatus, the melting of the product continues uninterruptedly to advance into connection 13, where it melts and then is transferred by worm 6 into the lower part of reservoir 1. During preliminary melting the solid product forms a sticky pulg preventing access of melt vapors into connection 13.

The sticky plug formed in the upper part of pipe chamber 8 prevents clogging of connection 13 when operating with sublimable products and at the same time it is pushed by worm 6 into the zone of final meltmg.

The initial product is transferred by worm 6, the melt is sucked in through openings 12 in wall of pipe 8 and is displaced, together with melted product, downwardly through the open end of pipe 8. Melt entering into pipe 8 through openings 12 provide heat to melt new portions of loose product being introduced at 13. Molten product are continuously drawn off through connection 18.

Intensive circulation of melt in the lower part of pipe 8 makes possible the rapid melting of loose product. Worm 6 insures immersion of preliminary melted product into a molten mass and removal of gas inclusions through openings 12.

Mixing means 7 can operate during the whole entire period of the melting process including the starting up period with the speed of rotation of the mixing member in the proposed apparatus for continuous melting being from 3 to 6 cm per sec, which allows a considerable improvement in the heat exchange between the wall of reservoir 1 and the molten mass as compared with conventional apparatus.

Together with realization of continuous melting of loose product, the proposed apparatus without any principal alteration can be widely used as a continuously operating reactor forcarrying out reactions between solid starting products or as melting apparatus for obtaining melts of given composition of several ingredients which do not react chemically.

When said apparatus is used as reactor, into the charging connection 13 is fed from a measuring hopper (not shown) a mixture of given composition of starting products which is moved by worm 6 along pipe 8.

The apparatus allows the achievement of a melting process under conditions of an inert gas atmosphere and pressure.

We claim:

1. Apparatus for melting loose material to a sublimal condition comprising in combination: a reservoir (1); means (15) for heating and melting material in said reservoir; means (18, 19) for drawing off a conditioned melt from the reservoir; a chamber (8) disposed axially within said reservoir including an open lower end communicating with said reservoir and an upper end for introducing loose material to be melted; initial heating means (9) operatively connected to said chamber (8) for initially heating loose material to be melted as it enters said chamber and before it enters the reservoir; power-operated, circulating conveyor means (6) extending axially through the chamber (8) for conveying loose and pre-heated material into said reservoir; said chamber including intermediate openings (12) communicating with said reservoir for recirculating a portion of the conditioned melt in the reservoir through said chamber (8) for supplementing the initial heating of the loose material being melted as it is introduced into said chamber.

2. The apparatus as claimed in claim 1 said circulating conveyor means comprising a screw conveyor disposed on an axial axis of rotation in said chamber;

said screw conveyor including a shaft depending into said reservoir; and

a mixing member connected toand rotating with said screw conveyor, and depending into said reservoir for mixing the conditioned melt produced therein.

3. The apparatus as set forth in claim 2 in which said mixing member includes blade portion disposed adjacent to and extending upwardly along the inner periphery of said reservoir for mixing the melt therein and promoting uniform distribution of heat inm the melt being conditioned.

4. The apparatus as claimed in claim 1 in which said heating means comprise jackets respectively surrounding said reservoir and chamber.

5. The apparatus as claimed in claim 1 in which said means for drawing off the melt comprise an outlet connection intermediately of said reservoir, and a lower converging sump portion including an outlet connection for draining the entire reservoir contents. 

1. Apparatus for melting loose material comprising in combination: a reservoir (1); means (15) for heating and melting material in said reservoir; means (18, 19) for drawing off a conditioned melt from the reservoir; a chamber (8) disposed axially within said reservoir including an open lower end communicating with said reservoir and an upper end for introducing loose material to be melted; initial heating means (9) operatively connected to said chamber (8) for initially heating loose material to be melted as it enters said chamber and before it enters the reservoir; power-operated, circulating conveyor means (6) extending axially through the chamber (8) for conveying loose and pre-heated material into said reservoir; said chamber including intermediate openings (12) communicating with said reservoir for recirculating a portion of the conditioned melt in the reservoir through said chamber (8) for supplementing the initial heating of the loose material being melted as it is introduced into said chamber.
 2. The apparatUs as claimed in claim 1 said circulating conveyor means comprising a screw conveyor disposed on an axial axis of rotation in said chamber; said screw conveyor including a shaft depending into said reservoir; and a mixing member connected to and rotating with said screw conveyor, and depending into said reservoir for mixing the conditioned melt produced therein.
 3. The apparatus as set forth in claim 2 in which said mixing member includes blade portion disposed adjacent to and extending upwardly along the inner periphery of said reservoir for mixing the melt therein and promoting uniform distribution of heat inm the melt being conditioned.
 4. The apparatus as claimed in claim 1 in which said heating means comprise jackets respectively surrounding said reservoir and chamber.
 5. The apparatus as claimed in claim 1 in which said means for continuously drawing off the melt comprise an outlet connection intermediately of said reservoir, and a lower converging sump portion including an outlet connection for draining the entire reservoir contents. 